Device and method of ablative cutting with helical tip

ABSTRACT

Catheter devices for ablation and removal of occlusions from blood vessels and methods of using the same are provided. Catheter devices are useful to ablate, cut, dislodge, and otherwise remove occlusions within a blood vessel that may limit or prevent proper circulation. Distal features of the catheter devices comprise arrangements of laser ablative or mechanical cutting features that generally provide enhanced surface areas and cutting functions. Spiral or helical arrangements are provided to aid in cutting operations.

FIELD

The present disclosure relates generally to medical devices, and, inparticular, to a system of improved irrigation and aspiration cathetersused in the containment and removal of material resulting fromtherapeutic treatment of occlusions within blood vessels.

BACKGROUND

Human blood vessels often become occluded or blocked by plaque, thrombi,other deposits, or emboli which reduce the blood carrying capacity ofthe vessel. Should the blockage occur at a critical place in thecirculatory system, serious and permanent injury, and even death, canoccur. To prevent this, some form of medical intervention is usuallyperformed when significant occlusion is detected.

Balloon angioplasty and other transluminal medical treatments arewell-known and have been proven efficacious in the treatment of stenoticlesions in blood vessels. The application of such medical procedures tocertain blood vessels, however, has been limited, due to the risksassociated with creation of emboli during the procedure. For example,angioplasty is not the currently preferred treatment for lesions in thecarotid artery because of the possibility of dislodging plaque from thelesion, which can enter the various arterial vessels of the brain andcause permanent brain damage. Instead, surgical procedures such ascarotid endarterectomy are currently used, wherein the artery is splitopen and the blockage removed, but these procedures present substantialrisks of their own.

Other types of intervention for blocked vessels include atherectomy,deployment of stents, introduction of specific medication by infusion,and bypass surgery. Each of these methods are not without the risk ofembolism caused by the dislodgement of the blocking material which thenmoves downstream. In addition, the size of the vessel may limit accessto it.

There is also a need to efficiently remove occlusions from a patientwithout excess undesired removal of native blood and tissue within thesystem. Constant flow suction or vacuum pressure is effective atremoving freed or dislodged occlusions, but typically remove unnecessaryamounts of blood in the process. Thus, there is a need for a system toeffectively contain and remove such emboli without undesiredconsequences, such as excess removal of blood and tissue from thevessel.

Vessels as small as 3 mm in diameter are quite commonly found in thecoronary arteries, and even certain saphenous vein graph bypass vesselscan also be as small as 3 mm or 4 mm; although some can range as high as7 mm. Certain of the carotid arteries also can be as small as 4 mm indiameter; although, again, others are larger. Nevertheless, a successfulemboli removal system must be effective within extremely small workingareas.

Another obstacle is the wide variety in emboli dimensions. Althoughdefinitive studies are not available, it is believed that emboli mayhave approximate diameters ranging anywhere from tens of micrometers toa few hundred micrometers. More specifically, emboli which areconsidered dangerous to the patient may have diameters as large as 200to 300 micrometers or even larger. Thus, an effective emboli removalsystem must be able to accommodate relatively large embolic particlesand, at the same time, fit within relatively small vessels.

Another difficulty that must be overcome is the limited amount of timeavailable to perform the emboli removal procedure. That is, in order tocontain the emboli produced as a result of intravascular therapy, thevessel must be occluded, meaning that no blood perfuses through thevessel to the end organs. Although certain perfusion systems may existor may be developed which would occlude emboli while permitting thesubstantial flow of blood, at present, the emboli may be contained onlywith a complete occlusion as to both blood flow and emboli escapement.Thus, again depending upon the end organ, the complete procedure,including time for the therapeutic treatment as well as exchanges ofangioplastic balloons, stents, and the like, must be completed within ashort time. Thus, it may be difficult to include time for emboli removalas well. This is particularly true in the larger size vessels discussedabove wherein a larger volume results in additional time required foremboli evacuation.

Additionally, there has been a long felt an unmet need to provide acatheter that is adept at removing harder material, such as calcium(e.g. harder than thrombus and plaque). Cutting and removal of suchharder materials generally requires additional procedure time andincreased risks.

Moreover, it is important that an emboli containment and removal systembe easy to use by physicians, and compatible with present therapeuticdevices and methods.

SUMMARY

These and other needs are addressed by the various aspects, embodiments,and configurations of the present disclosure.

In various embodiments, a laser cutting and aspiration atherectomysystem is provided, the system comprising a catheter comprising a ringor distribution of fibers that provide a cutting function and an innerlumen through which aspirated material is removed from a patient. It iscontemplated that material be removed from the lumen by, for example, apulsed aspiration system and an in-line filter for material collectionas described herein. Embodiments of laser cutting and aspirationatherectomy systems of the present disclosure provide for a wide arrayof benefits, including providing the ability to create visibly smootherlumens faster than conventional laser ablation methods and systems.Embodiments of the present disclosure ablate less native tissue,separate the lesion from the vasculature in pieces or plugs, andaspirate material through the catheter. With a deflection component,this design can be used to both create a pilot channel and subsequentlarger channels, faster than conventional bulk ablation. Devices of thepresent disclosure create a pilot channel and larger lumens in a fastermanner than convention bulk ablation methods and devices.

Embodiments of the present disclosure contemplate various mechanicalcutting features provided in combination with a catheter, either inaddition to or in lieu of laser ablation means. Such mechanical cuttingfeatures include, but are not limited to, various bladed or shearingdevices provided at or proximal to a distal end of the catheter. Suchmechanical cutting features are contemplated as being substantiallyfixed to a distal end of a catheter, such as the periphery of an annulardistal end, or selectively retractable/extendable from the distal endsuch that the cutting features are only provided in a position of usewhen desired. An example of a device that include a mechanical sheathfor extending a cutting blade from the distal end of the sheath aredescribed and illustrated in U.S. Pat. No. 5,651,781 to Grace, which ishereby incorporated herein by reference in its entirety for all that itteaches and for all purposes.

In one embodiment, a laser cutting and aspiration atherectomy catheteris provided, the catheter comprising an outer jacket with a taperedouter band, an inner lumen or channel for passage of material, and atleast one ring or circular array of cutting fibers. A narrowed orificeor inner band is provided at the distal tip of the catheter. In apreferred embodiment, the catheter comprises a flexible tip withdeflection items such as pull wires or shaping wires. Such deflectionitems are provided in addition to or in lieu of a distal outer jacket.The outer jacket provides a rigid member for communication of varioususer-applied forces including, but not limited to, torque, compression,and tension forces. The inner lumen provides a reinforced, lubriciouslumen for material aspiration. The lumen, in certain embodiments,comprises a coil reinforced polytetrafluoroethylene/polyimide composite.Cutting fibers provide or transmit laser energy for cutting plaque andother occlusive material. In preferred embodiments, the fibers comprise100 μm fibers provided in concentric arrangements (with respect to oneanother and/or the catheter).

In various embodiments, one or more catheters of the present disclosureare provided to remove cores or plug-shaped features from an occludedvessel. Devices and methods of the present disclosure contemplatecutting and removing of discrete portions of an occlusions, such assubstantially cylindrical portions generally corresponding to theshape/diameter of a catheter distal end and inner lumen. Accordingly,and in contrast with prior art systems and devices, the presentdisclosure comprises the ability to remove discrete plugs or sections ofan occlusion and minimize particulate that may be translocated todifferent locations within a system and cause additional complications.Annular cutting features, such as ablative lasers and/or mechanicalcutting features, inner lumen removal systems, and structural featuresof catheters that enable application of axial of compression force tothe catheter, for example, provide means for extracting discrete plugsor clogs of material from an occlusion and restoration of blood flowthrough an occlusion.

A method for removing occlusions from a vessel is provided, the methodcomprising the steps of providing an aspiration catheter comprising: (i)a distal end of substantially annular construction, the substantiallyannular construction defining an inner lumen for conveyance of material;(ii) at least one cutting element provided coincident or distal with theinner lumen; and (iii) a vacuum pump in fluid communication with theinner lumen and operable to transmit material therethrough; insertingthe distal end of the aspiration catheter into a blood vessel navigatingthe distal end to a site of stenosis, selectively activating appropriatecutting element parameters, activating the vacuum pump, manipulating theaspiration catheter to extract a stenotic material, the stenoticmaterial comprising a cross-sectional substantially the same as across-section of the inner lumen, and conveying the stenotic materialthrough the length of the catheter.

The narrowed orifice provides a limiting orifice for material transportand clog resistance and, in certain embodiments, comprises a thin wall,stainless steel hypotube. The outer band provides fiber reinforcementand radio-opacity and, in certain embodiments, comprises aplatinum-iridium band.

In one embodiment, a catheter is provided comprising an outer jacket,the outer jacket providing protection for internally-disposed fibers andaiding in maintaining the integrity of the inner lumen(s). The outerjacket further provides enhancements in control of the device, includingflexibility of the catheter, track-ability along a path, and enhancedability to accommodate and/or transmit torque and compression.Preferably, a tricoil arrangement is provided. In alternativeembodiments, braided Pebax®, braided polyimide, and Pebax® jackets areprovided.

As used herein, a “tricoil” arrangement comprises a shaft comprisingcoiled wire in a plurality of layers. In certain embodiments,construction of a tricoil includes wrapping at least one round or flatwire in one direction, either clockwise or counter-clockwise around acore mandrel. The wires are wrapped side by side and secured when anappropriate length is achieved. A second layer of at least one round orflat wires is wound in the opposite direction on top of the first layerand secured. The final layer of at least one round or flat wire is woundin the opposite direction of the second layer (or the same direction asthe first layer) and secured. The assembly is then welded together atthe ends of the shaft to create the component. Wire dimensions and countcan be varied in construction for various attributes.

Tricoils contemplated by the present disclosure include, but are notlimited to 1-4-4 and 1-6-6 filar count by layer, with flat wires from0.0014″×0.010″ to 0.002″×0.016″. Benefits of tricoils include extremetorquability (approaching 1:1 ratio of torque input to torque output,even in bends), kink resistance, inner lumen protection, and durability,to name a few.

Alternative catheter shaft constructions include, but are not limited toPebax, Braided Pebax, Braided Polyimide, Bicoils, and variouscombinations thereof.

Inner lumens of catheters of the present disclosure provide a conduit orpathway for aspirating cut or ablated material out of the body. Invarious embodiments, a vacuum-sealed, lubricious inner surface isprovided that does not substantially deform or kink, so as to facilitateconsistent removal of material without clogging the device. In certainembodiments, the lumen comprises a coil-reinforced,polytetrafluoroethylene/polyimide composite that provides sufficienthoop strength while allowing for a lubricious inner surface. Inadditional embodiments, a braid-reinforced PTFE/polyimide composite isprovided for the inner lumen. In yet additional embodiments, the innerlumen may have ridges formed in a rifle-like manner to further controlthe removal of the material.

In certain embodiments, a catheter is provided comprising an internalrifled feature. A catheter jacket is contemplated as comprising aninternal feature of a spiral and/or spinning helix or screwconfiguration. The jacket, which may be a polymer extrusion, comprises ahelical rib or rifle such that rotation of the catheter about alongitudinal axis aspirates and/or macerates material. Extension and/orrotation of the catheter induces rotation of the helix structure,thereby freeing material and enabling removal. Freed material may beconveyed from a vessel via a central lumen of the catheter, for example.

The design of the inner lumen is essential to the removal of materialwithout clogging. Requirements for the inner lumen include ovaling/kinkresistance, vacuum compression resistance, and inner surface lubricity.Inner lumens that we have tried have been mostly composed of some typeof Polyimide construction. We have used pure Polyimide lumens,PTFE/Polyimide Composite lumens, Pure PTFE inner liner with aPTFE/Polyimide composite outer layer. Reinforcement to the inner lumenshas consisted of stainless steel wire braids and coils embedded into thewalls of the lumen. These reinforcements prevent kinking, ovaling, andvacuum compression. Inner lumen design could consist of any combinationsof components listed in the shaft design section.

Fibers of the present disclosure are provided to deliver laser energy,including that produced by a Spectranetics® CVX-300 and relatedinterface circuit, for example. It is contemplated that fibers of thepresent disclosure be protected from damage and oriented correctly atthe distal tip of the catheter for laser ablation. In variousembodiments, approximately fifty to one hundred fibers are provided inconcentric annular rings. In a preferred embodiment, seventy four 100 μmfibers are provided in concentric circles. This particular embodimentprovides for sufficient energy to ablate tissue, while leaving enoughroom for a sufficiently large inner lumen space. It will be recognized,however, that the present disclosure is not limited to a particularnumber or arrangement of fibers. Indeed, various alternativearrangements and quantities of cutting fibers are contemplated as withinthe scope and spirit of the present disclosure. In alternativeembodiments, any combination of fiber size can be utilized, includingbut not limited to 61/100/130 μm fibers, either in substantiallycircular or ovoid cross-section.

In various embodiments, a narrowed orifice/inner band is provided thatcreates a limiting orifice at the distal tip of the catheter. Thenarrowed orifice helps ensure that if material can pass through it, itwill fit down the remainder of the inner lumen. Additionally, thenarrowed orifice provides a rigid inner member for fiber support andprevents inner lumen degradation and damage. In one embodiment, a short,thin wall stainless steel hypotube is provided for the narrowed orifice.The shortness of the orifice decreases the chances of clogging at thetip, while the thin wall design reduces the amount of dead space forlaser ablation.

In various embodiments, an outer band is provided at the distal end ofthe catheter, the outer band providing a rigid structure for fibersupport and protection as well as ease of manipulation of fiberplacement within the distal end. The present disclosure contemplates oneor more bands or rows of fibers. One, two, or three or moresubstantially concentric rows of fibers may be provided for ablatingmaterial.

In one embodiment, a Pt/Ir band of approximately 2.0 mm diameter isprovided that tapers to approximately 2.3 mm in diameter. Althoughvarious embodiments contemplate Pt/Ir bands, any biocompatible materialincluding, but not limited to, stainless steel, plastic, etc. may beused to confine fibers. Outer band embodiments of the present disclosureprovide for grouping of at least the distal ends of the fibers proximatean inner band, thus focusing the laser energy and allowing for more ofthe laser energy to create smaller plugs of material. It is furthernoted that such embodiments provide for a manufacturing “stop” when theflared inner lumen fits into the preferably tapered portion of the band.Although various embodiments contemplate a tapered outer band,non-tapered bands are also contemplated by the present disclosure.

Catheters of the present disclosure comprise one or more polishedsurfaces that dictate the interaction of the tip with a surfaceencountered by the tip. Various embodiments comprise flat polished facesthat engage tissue concentrically. Preferably, a flat polish is providedthat allows not only the fiber faces to engage tissue at the same time,but also allows the inner lumen to form a vacuum seal on tissue thatfills the distal face.

Deflection means are provided in various embodiments of the presentdisclosure for user-selective manipulation of a distal end of acatheter. In various embodiments, deflection means comprise featuresinvolved in offsetting or deflecting the catheter tip, such that alarger lumen may be created in an occlusion, as compared withnon-deflective or offset manipulation of the catheter. It iscontemplated that deflection means of the present disclosure provide forbetween approximately 2-5 mm offsets from an initial or alignedpositioned, and preferably for between approximately 3-4 mm offsets,particularly for “above the knee” procedures.

In certain embodiments, one or more pullwires are provided as deflectionmeans. Pullwires of the present disclosure comprise wires that run downthe length of the catheter and are attached to the distal tip formanipulation thereof. When a tension force is applied to at least onedeflection means of such embodiments, the wire(s) causes deflection ofthe flexible distal end of the catheter. In one embodiment, a wirecomponent is provided in the catheter that is permanently fixed to thedistal portion of the catheter. User manipulation of the wire, forexample at a user-proximal portion of the catheter, is effective toshape the wire and catheter to a particular desired shape for largerlumen creation. In an additional embodiments, a balloon feature isprovided comprising a non-compliant balloon fastened to the distal tipthat, when inflated, causes deflection preferentially to one side of acorridor. Additionally, ramped features, such as those shown andescribed in U.S. Pat. No. 5,484,433 to Taylor et al., which is herebyincorporated by reference in its entirety may be included withincatheters of the present disclosure.

Embodiments of the present disclosure also contemplate a flexible tipprovided in combination with deflection means such as a shaping spine orpullwire. A flexible portion at the distal tip allows for bends andangled to be induced at the intended site, while the rest of thecatheter can remain straight and rigid. In certain embodiments, lasercut hypotubes are provided having a thick enough wall for flexingwithout buckling and kerf widths (laser cut widths) large enough toallow for the bend angle required. Such tips are attached to the end ofthe catheter by laser welding (with a tricoil) or a fuse joint(plastics) and can be cut to preferentially bend a certain direction.Additionally, Pebax segments may be provided, such segments being fusedto the end of a tricoil and able to deflect using a pullwire and/orshaping wire. Employing polymer tubing, a wire coil, or a combinationthereof for the distal body, a guide wire may be used in peripheral orcoronary angioplasty applications.

Various embodiments of the present disclosure also contemplate aspiraled ring ablation device with a mechanical cutting tip at thedistal end of the catheter. A laser fiber ring is provided for cuttingtissue while a blade or mechanical cutting edge assists in cutting andremoval of harder calcium deposits, for example. The distal end may alsobe rotatable at various speeds to create various motions with themechanical cutting edge. The edges of a spiral band may further beprovided with mechanical cutting features. Thus, in various embodiments,a catheter is provided with a combination of laser and mechanicalcutting or ablation features. Cutting efficiencies, particular withrespect to calcium deposits, are thus improved.

Concurrent extension and rotation of at least a distal end of a catheterof the present disclosure is provided as a means for cutting andablating an obstruction. In one embodiment, a method of removingmaterial from a blood vessel is contemplated, the method comprising thestep of concurrently extending a catheter along a length of a vessel androtating at least the distal end of the catheter. Such methods providevarious advantages, including the ability to core out or extract asubstantially cylindrical mass of material and providing a fluid flowcorridor through an obstruction, thus enabling fluid/blood flow throughthe corridor even when complete removal or ablation of the obstructionis not performed.

Various embodiments of the present disclosure contemplate a pulsedvacuum aspiration system to evacuate material removed during anatherectomy procedure and remove material as it is ablated and moveddown the shaft of a vacuum device in a pulsed manner.

Although pulsed aspiration systems are contemplated with variousfeatures shown and described herein, the features, systems and methodsdescribed herein are not limited to use with pulsed aspiration systemsand methods. Indeed, various removal means, devices and methods arecontemplated for use with various features of the present disclosure.Such means, devices and methods include, but are not limited to,spinning helixes, rotating screws, Archimedes screws, continuous vacuumaspiration, and various combinations thereof. Additionally, aspirationsystems other than a pulsed aspiration systems may be used. For example,an additional embodiment may include the use of a peristaltic pump formaterial aspiration in conjunction with laser cutting and coring. Use ofthe peristaltic pump may negate the use of a solenoid valve or pulsewidth modulator, due to the nature of peristaltic pump materialmovement. The peristaltic pump embodiment differs mainly from the vacuumpump embodiment in that it relies on a liquid filled system to aspirateor move material, while the vacuum pump system utilizes both air andliquid filled system, leading to potential variability within the systemdue to the compressibility nature of air. With reference to FIG. 4, if aperistaltic pump is used, then the vacuum pump 18 would be replaced witha peristaltic pump and the solenoid valve 22 and pulse width modulator20 would be deleted.

Other disclosures include using mechanical or laser means tomacerate/destroy material as it enters the inner lumen.

In various embodiments, one or more vacuum pumps are provided togenerate the vacuum required to aspirate material down a central lumenof a catheter. Vacuum levels in the range of 10 to 30 in-Hg, andpreferably approximately 20 in-Hg, are provided. Vacuum pumps of thepresent disclosure preferably comprise a disposable collectioncontainer.

Another aspect of the present disclosure comprises a clogging detectionmeans which detects clogging in an aspiration tube or an aspirationcatheter during an aspiration operation.

In certain embodiments, an aspirator includes clogging detection meansfor measuring a change in a flow rate of an aspirate at one more pointsin a system. Alternatively, clogging detection means comprise means formeasuring a change in a weight of an aspirate sampling bottle and/or achange in an amount of aspiration dropping in an aspirate samplingbottle. In various embodiments, clogging alert means for informing auser that clogging in the aspiration tube or the aspiration catheter hasoccurred are provided.

Clogging alert means of the present disclosure include, but are notlimited to warning sounds and/or visual indicators that immediatelynotify a user of a potential clog such that remedial action can be takenimmediately.

In one embodiment, an aspirator is provided with clogging detectionmeans, the clogging detection means comprising a load cell for measuringthe weight of an aspirate collection feature, such as a sampling jar.When clogging in the aspiration catheter or the aspiration tube occurs,a rate of increase in the weight of the collection features decreases.Therefore, clogging in the aspiration catheter or the aspiration tubecan be detected by measuring a change in weight of the aspiratecollection feature with the load cell. Where clogging is detected, awarning indicia is provided to inform an operator that the clogging haspotentially occurred.

In alternative embodiments, detection of clogging is performed bymeasuring a change in a flow rate of an aspirate at one or more pointsin the system, such as blood flow in the aspiration catheter and/or theaspiration tube. For example, flow rate in a part of an aspiration tubeimmediately before an aspirate collection device is continuouslymeasured by a flowmeter, an ultrasonic wave flowmeter, or the likeduring an aspiration operation. When a flow rate falls to a set value orless, it can be judged that clogging has occurred.

In still further embodiments, clogging or blockage is detected based onmonitoring pressure values at one or more points in a system. Since anaspiration pressure increases when the aspiration catheter or theaspiration tube is blocked, when the aspiration pressure rises to a setvalue or more, it can be judged that clogging has occurred. It is alsopossible to set a threshold value for an output to the pressureindicator and emit a warning when the output increases to the thresholdvalue or more.

When clogging in the aspiration catheter or the aspiration tube hasoccurred, it is preferable that an operator is informed to that effectimmediately, and prompt measures for restart of aspiration are taken.Examples of the clogging alert means emitting a warning indicia include,but are not limited to a buzzer, a bell, various electronic sounds, andartificial voices. The clogging alert means is not specifically limited.If the alert means using a warning sound is adopted, an operator canconcentrate on manipulation sufficiently and safety of an operation or apatient is remarkably improved because it is unnecessary for theoperator to look at the medical aspirator in order to monitor cloggingduring the manipulation. Clogging alert means are further contemplatedas comprising visual indicia, including various lamps, LEDs, or thelike.

Embodiments of the present disclosure contemplate a vacuum system withclog detection features. Such embodiments comprise means to detect adifference in vacuum pressure, such as when a clog or obstruction isprovided in a vacuum line and means to alert a user or operator of thedevice. Alert means of the present disclosure include, but are notlimited to, auditory and visual feedback features to identify to theuser that a clog in the vacuum system is present or likely present.

In one embodiment, alert means comprise a mechanical switch or featurethat is activated upon a pressure value in a vacuum system exceeding apredetermined value. For example, a weighted or pressurized element isprovided in a manner wherein the element is substantially hidden from auser's view when the vacuum is operating under normal unobstructedconditions. However, upon the pressure value exceeding a predeterminedvalue, such as that corresponding to a significant blockage in thevacuum system, the element is displaced to a position whereby it isvisible to a user. Such an embodiment provides a “red flag” warningindicia to a user that the vacuum is not operating normally and anobstruction may be present.

In a further embodiment, alert means comprise audio and/or visualindicia prompted by a waveform output of vacuum pressure at a particularpoint in the system. For example, a vacuum system is provided with oneor more electromechanical pressure sensing features, such featuresoutputting a waveform corresponding to pressure values at one or morepoints over time. Where at least one of such pressure values exceeds(thus indicating an upstream blockage) or drops below (thus indicating adownstream blockage) a predetermined value, the detected value promptsan associated audio and/or visual alarm to indicate to a user thepresence of one or more blockages.

A method of operating a vacuum assisted aspiration system is provided,the method comprising the steps of: prepping and priming a catheter forsurgery, inserting the catheter into a patient via a sheath, navigatingthe catheter to a site of stenosis (e.g. via guidewire), selectingappropriate mechanical and/or laser cutting parameters, activatingappropriate mechanical and/or laser cutting features, activating apulsed aspiration system via a foot pedal or similar user-actuationmeans, manipulating the catheter to core out stenotic material, applyinglaser energy and/or mechanical means to core material, and transmittingmaterial into a distal tip of the catheter and subsequently conveyingthe material through the length of the catheter. A user may subsequentlyrepeat various aforementioned steps until a stenosis is adequatelyremoved or remedied. In embodiments comprising clog detection means,wherein a lesion material becomes clogged within the system, vacuumpressure will increase at a point in the system. Wherein such acondition occurs, alert means indicate to a user the presence of a clog.The user may then take correction, such as removing the device from thepatient, purging the catheter, and subsequently re-employing the devicefor subsequent operations.

In one embodiment, a custom vacuum pump is provided. Alternatively,known and/or commercially available pumps, such as personal patientpumps are provided. It will be recognized that the present disclosure isnot limited to any specific pump size, power, displacement etc.Preferably, however, one or more pumps of small, lightweight design thatcan still create and maintain the required vacuum levels are provided.

Various vacuum systems of the present disclosure comprise one or moresolenoid valves to open and close a line between the vacuum pump and theaspiration lumen of the catheter. Such valves are compatible with blood,are liquid sealed, and have a fast response time for opening and closingat high frequencies.

In various embodiments, a custom valve is provided that is small, fastresponding and can be fully integrated with the pump and othercircuitry. The valve(s) may be disposable with the rest of the system orreusable (e.g. with the proper filters).

One or more filters are provided to collect material being aspirateddown the inner lumen of the catheter. Filters of the present disclosureare provided with, for example, Luer valve fittings for ease of use,removal, cleaning, and reattachment. One filter of the presentdisclosure comprises Luer valve sides of two syringes with a plasticgrate inside. The pore size of the grate is large enough to let liquidmove through unimpeded, but small enough to prevent material from goingthrough the valve into the disposable collection jar.

Pulsed vacuum systems of the present disclosure comprise a pulse widthmodulator to provide various signals to a valve, causing the valve toreact faster/slower and remain open/closed for longer amounts of time.

Pulsing characteristics can be programmed into the vacuum pump/valve,and/or controlled by a user-operable feature such as a manual device orfoot-pedal. In certain embodiments, a delay is built into an interfacecircuit of the present disclosure, the delay provided to allow thevacuum pump to run for a set amount of time after cutting operationshave ceased, thereby allowing the inner lumen and other aspirationcorridors to clear of material, thus reducing risk of back-flow andproviding the benefit of generally clearing or purging the system. Thedelay may be programmed to allow the vacuum to run various durations. Itwill be recognized, however, that a preferred duration is one thataccounts for length of lumen/corridor and flow rate and thus providessufficient clearing of the system.

Preferably, a preset/adjustable custom circuit is provided, the customcircuit designed for pulsed aspiration in combination with additionalfeatures. The circuit comprises a user interface for adjustment, or isalternatively completely preset. In one embodiment, an interface circuitis provided that interfaces with a laser excimer system foot pedal, suchas that associated with the Spectranetics® CVX-300, allowing foractivation of the pulsed aspiration system only when lasing is activelyoccurring, thus further reducing the amount of undesired or unnecessaryfluid transferred from a patient. A delay is built into the circuit toallow the vacuum pump/valve to run for a set amount of time after lasingso that the inner lumen can clear material. Such a delay may bepre-programmed based on various system characteristics including, butnot limited to, the length of the inner lumen.

The present disclosure can provide a number of advantages depending onthe particular configuration. Advantages of embodiments of the presentdisclosure include, but are not limited to, the evacuation ofparticulate and occlusions from an atherectomy site as such particulateis generate, thus reducing the risk of mere translocation of theparticulate to other areas of the circulatory system. Variousembodiments of the present disclosure contemplate user-selectedpulsation of a vacuum or removal system such that the system may bepulsed only as particulate generation is occurring, decreasing thevolume of blood or fluid extracted from a patient.

Additionally, pulsation features of the present disclosure are capableof providing short duration peak vacuum pressures that enhance thedevice's ability to evacuate larger or higher friction particles. Pulsedaction methods and devices create a stepped motion from the extractionsite down a catheter shaft, for example. Pulse width and duty cycle ofthe vacuum pulse can be varied to optimize the particle aspirationprocess for highest efficiency and minimum blood and fluid removal.

In various embodiments, the device of the present disclosure may notonly be used for dissecting, coring and aspirating plug-type portions oflesion material, but the device or embodiments of the device of thepresent disclosure may be used to perform bulk ablation. Bulk ablationgenerally encompasses the use of catheter having a full face of laseremitters at its distal end, and all of the lesion material contacted bythe energy transmitted by the laser emitters is ablated, in comparisonto ablating the lesion with a circular or helical arrangement of lasersand coring the tissue. Depending upon the size and type of lesion, thebulk ablation technique may potentially increase the efficiency of thesystem and removal of debris. Such a technique may be used by auser/physician based on the specific removal needs and may comprise, forexample, inserting an additional laser catheter through a central lumento provide a substantially flat laser ablation distal end of thecatheter.

Various embodiments of the present disclosure contemplate mechanicalmaterial removal means, such as helixes and screws. In one embodiment, amethod and system is provided comprising a stainless steel hypotubefurther comprising a helical structure, the helical structure is capableof rotation at, for example, at approximately 15,000 to approximately100,000 RPM. Such helical structure(s) are capable of macerating andtranslating material along their length, and thus removing occlusionsfrom a vessel. Helical structures of the present disclosure may beprovided in combination with various vacuum systems, laser andmechanical ablation systems, and other features described herein toassist in removal of material.

In various embodiments, a system is provided with user-selected presetsfor pulsed vacuum aspiration modes. For example, in one embodiment, aplurality of settings are provided in connection with a pulse widthmodular such that a user/physician may select between general vacuumaspiration settings including “low,” “medium,” and “high” based on theuser's first-hand knowledge of the amount of particulate being evacuatedor desired to be evacuated.

In various embodiments, one or more filters are applied, such as catchfilters that allow a physician to visualize and/or analyze materialbeing removed from an aspiration site.

These and other advantages will be apparent from the disclosure of theaspects, embodiments, and configurations contained herein.

As used herein, “at least one”, “one or more”, and “and/or” areopen-ended expressions that are both conjunctive and disjunctive inoperation. For example, each of the expressions “at least one of A, Band C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “oneor more of A, B, or C” and “A, B, and/or C” means A alone, B alone, Calone, A and B together, A and C together, B and C together, or A, B andC together. When each one of A, B, and C in the above expressions refersto an element, such as X, Y, and Z, or class of elements, such asX₁-X_(n), Y₁-Y_(m), and Z₁-Z_(o), the phrase is intended to refer to asingle element selected from X, Y, and Z, a combination of elementsselected from the same class (e.g., X₁ and X₂) as well as a combinationof elements selected from two or more classes (e.g., Y₁ and Z_(o)).

It is to be noted that the term “a” or “an” entity refers to one or moreof that entity. As such, the terms “a” (or “an”), “one or more” and “atleast one” can be used interchangeably herein. It is also to be notedthat the terms “comprising”, “including”, and “having” can be usedinterchangeably.

The term “automatic” and variations thereof, as used herein, refers toany process or operation done without material human input when theprocess or operation is performed. However, a process or operation canbe automatic, even though performance of the process or operation usesmaterial or immaterial human input, if the input is received beforeperformance of the process or operation. Human input is deemed to bematerial if such input influences how the process or operation will beperformed. Human input that consents to the performance of the processor operation is not deemed to be “material”.

A “catheter” is a tube that can be inserted into a body cavity, duct,lumen, or vessel, such as the vasculature system. In most uses, acatheter is a relatively thin, flexible tube (“soft” catheter), thoughin some uses, it may be a larger, solid-less flexible—but possibly stillflexible—catheter (“hard” catheter).

The term “computer-readable medium” as used herein refers to any storageand/or transmission medium that participate in providing instructions toa processor for execution. Such a medium is commonly tangible andnon-transient and can take many forms, including but not limited to,non-volatile media, volatile media, and transmission media and includeswithout limitation random access memory (“RAM”), read only memory(“ROM”), and the like. Non-volatile media includes, for example, NVRAM,or magnetic or optical disks. Volatile media includes dynamic memory,such as main memory. Common forms of computer-readable media include,for example, a floppy disk (including without limitation a Bernoullicartridge, ZIP drive, and JAZ drive), a flexible disk, hard disk,magnetic tape or cassettes, or any other magnetic medium,magneto-optical medium, a digital video disk (such as CD-ROM), any otheroptical medium, punch cards, paper tape, any other physical medium withpatterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, a solidstate medium like a memory card, any other memory chip or cartridge, acarrier wave as described hereinafter, or any other medium from which acomputer can read. A digital file attachment to e-mail or otherself-contained information archive or set of archives is considered adistribution medium equivalent to a tangible storage medium. When thecomputer-readable media is configured as a database, it is to beunderstood that the database may be any type of database, such asrelational, hierarchical, object-oriented, and/or the like. Accordingly,the disclosure is considered to include a tangible storage medium ordistribution medium and prior art-recognized equivalents and successormedia, in which the software implementations of the present disclosureare stored. Computer-readable storage medium commonly excludes transientstorage media, particularly electrical, magnetic, electromagnetic,optical, magneto-optical signals.

A “coupler” or “fiber optic coupler” refers to the optical fiber devicewith one or more input fibers and one or several output fibers. Fibercouplers are commonly special optical fiber devices with one or moreinput fibers for distributing optical signals into two or more outputfibers. Optical energy is passively split into multiple output signals(fibers), each containing light with properties identical to theoriginal except for reduced amplitude. Fiber couplers have input andoutput configurations defined as M×N. M is the number of input ports(one or more). N is the number of output ports and is always equal to orgreater than M. Fibers can be thermally tapered and fused so that theircores come into intimate contact. This can also be done withpolarization-maintaining fibers, leading to polarization-maintainingcouplers (PM couplers) or splitters. Some couplers use side-polishedfibers, providing access to the fiber core. Couplers can also be madefrom bulk optics, for example in the form of microlenses and beamsplitters, which can be coupled to fibers (“fiber pig-tailed”).

The terms “determine”, “calculate” and “compute,” and variationsthereof, as used herein, are used interchangeably and include any typeof methodology, process, mathematical operation or technique.

A “laser emitter” refers to an end portion of a fiber or an opticalcomponent that emits laser light from a distal end of the cathetertowards a desired target, which is typically tissue.

An optical fiber (or laser active fibre) is a flexible, transparentfiber made of an optically transmissive material, such as glass (silica)or plastic, that functions as a waveguide, or “light pipe”, to transmitlight between the two ends of the fiber.

The term “means” as used herein shall be given its broadest possibleinterpretation in accordance with 35 U.S.C., Section 112, Paragraph 6.Accordingly, a claim incorporating the term “means” shall cover allstructures, materials, or acts set forth herein, and all of theequivalents thereof. Further, the structures, materials or acts and theequivalents thereof shall include all those described in the summary ofthe invention, brief description of the drawings, detailed description,abstract, and claims themselves.

It should be understood that every maximum numerical limitation giventhroughout this disclosure is deemed to include each and every lowernumerical limitation as an alternative, as if such lower numericallimitations were expressly written herein. Every minimum numericallimitation given throughout this disclosure is deemed to include eachand every higher numerical limitation as an alternative, as if suchhigher numerical limitations were expressly written herein. Everynumerical range given throughout this disclosure is deemed to includeeach and every narrower numerical range that falls within such broadernumerical range, as if such narrower numerical ranges were all expresslywritten herein.

The preceding is a simplified summary of the disclosure to provide anunderstanding of some aspects of the disclosure. This summary is neitheran extensive nor exhaustive overview of the disclosure and its variousaspects, embodiments, and configurations. It is intended neither toidentify key or critical elements of the disclosure nor to delineate thescope of the disclosure but to present selected concepts of thedisclosure in a simplified form as an introduction to the more detaileddescription presented below. As will be appreciated, other aspects,embodiments, and configurations of the disclosure are possibleutilizing, alone or in combination, one or more of the features setforth above or described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are incorporated into and form a part of thespecification to illustrate several examples of the present disclosure.These drawings, together with the description, explain the principles ofthe disclosure. The drawings simply illustrate preferred and alternativeexamples of how the disclosure can be made and used and are not to beconstrued as limiting the disclosure to only the illustrated anddescribed examples. Further features and advantages will become apparentfrom the following, more detailed, description of the various aspects,embodiments, and configurations of the disclosure, as illustrated by thedrawings referenced below.

FIG. 1 is a top perspective view of a distal end of a catheter accordingto one embodiment of the present disclosure;

FIG. 2 is an elevation view of a distal end of a catheter according toone embodiment of the present disclosure;

FIG. 3 is cross-sectional view of a distal end of a catheter accordingto one embodiment of the present disclosure;

FIG. 4 is a schematic of a pulsed vacuum system according to oneembodiment of the present disclosure;

FIG. 5 is a perspective view of a distal end of a catheter according toone embodiment of the present disclosure;

FIG. 6 is an elevation view of a distal end of a catheter according toone embodiment of the present disclosure;

FIG. 7 is an elevation view of a distal end of a catheter according toone embodiment of the present disclosure;

FIG. 8 is a perspective view of a distal end of a catheter according toanother embodiment of the present disclosure;

FIG. 9A, is a perspective view of a distal end of a catheter having acutting blade at its distal tip in a retracted position according to oneembodiment of the present disclosure;

FIG. 9B, is a perspective view of a distal end of a catheter having acutting blade at its distal tip in an extended position according to oneembodiment of the present disclosure;

FIG. 10A, is a perspective view of a distal end of a catheter having acutting blade at its distal tip in a retracted position according toanother embodiment of the present disclosure;

FIG. 10B, is a perspective view of a distal end of a catheter having acutting blade at its distal tip in an extended position according toanother embodiment of the present disclosure; and

FIG. 11A is a cross-sectional elevation view of a catheter according toone embodiment;

FIG. 11B is a phantom perspective view of a catheter according to oneembodiment.

DETAILED DESCRIPTION

Although a large portion of this disclosure includes a discussion oflaser catheters (or catheters having a combination of laser emitters andmechanical cutting tips at the distal end its distal end,) used inconjunction with an aspiration system, catheters having mechanicalcutting tips may also be used. Laser catheters typically transmit laserenergy through optical fibers housed in a relatively flexible tubularcatheter inserted into a body lumen, such as a blood vessel, ureter,fallopian tube, cerebral artery and the like to remove obstructions inthe lumen. Catheters used for laser angioplasty and other procedures mayhave a central passageway or tube which receives a guide wire insertedinto the body lumen (e.g., vascular system) prior to catheterintroduction. The guide wire facilitates the advancement and placementof the catheter to the selected portion(s) of the body lumen for laserablation of tissue.

Examples of laser catheters or laser sheaths are sold by theSpectranetics Corporation under the tradenames ELCA™ and Turbo Elite™(each of which is used for coronary intervention or catheterization suchas recanalizing occluded arteries, changing lesion morphology, andfacilitating stent placement) and SLSII™ and GlideLight™ (which is usedfor surgically implanted lead removal). The working (distal) end of alaser catheter typically has a plurality of laser emitters that emitenergy and ablate the targeted tissue. The opposite (proximal) end of alaser catheter typically has a fiber optic coupler, which connects to alaser system or generator. One such example of a laser system is theCVX-300 Excimer Laser System, which is also sold by the SpectraneticsCorporation.

Referring now to FIGS. 1-2, a distal end of a laser catheter 2 foratherectomy procedures in accordance with one embodiment of the presentdisclosure is shown. The laser catheter 2 may (as depicted in FIGS. 1and 2) or may not include a lumen 14. If a lumen 14 is included in thelaser catheter 2, a clinician may slide the laser catheter over aguidewire (not shown) through lumen 14. It may, however, be preferablefor the catheter to have a separate guidewire lumen located between theinner band and outer jacket. Incorporation of such a guidewire lumen isgenerally known to one of ordinary skill in the art, and all suchguidewire lumens are within the knowledge of one skilled in the art areconsidered within the scope of this disclosure.

As shown, the catheter 2 comprises an outer jacket 4 or sleeve. Theouter jacket 4 comprises a flexible assembly with the ability to resistuser-applied forces such as torque, tension, and compression. Theproximal end (not shown) of the catheter 2 is attached to a fiber opticcoupler (not shown) and includes an outer jacket, inner band and aplurality of optical fibers similar to the configuration and orientationof such components depicted in FIGS. 1 and 2. The distal end 6 of thecatheter 2 comprises a tapered outer band 8, which is attached to thedistal end of the outer jacket 4, a plurality of optical fibers 10acting as laser emitters, inner band 12 creating an orifice thatprovides an entrance to an inner lumen 14 that is connected to anaspiration system discussed in more detail below. The energy emitted bythe laser emitters 10 cuts, separates, and/or ablates the scar tissue,plaque build-up, calcium deposits and other types of undesirable lesionor bodily material within the subject's vascular system in a patternsubstantially similar to that of the cross sectional configuration ofthe laser emitters 10.

The cutting means in this embodiment is a laser ablation means thatincludes laser emitters 10 embedded within a catheter 2 comprising alumen 14. In this particular embodiment, approximately seventy-fourlaser emitters 10 are provided in a generally concentric configuration.Also provided substantially concentric with and interior to the laseremitters 10 (and optical fibers) is an inner lumen 14, which provides apotential conduit or passageway for translocation of materials cut orablated by the laser emitters 10.

As the energy emitted by the laser emitters 10 contacts the undesirablebodily material within the subject's vascular system, it separates andcuts such material in a generally concentric configuration. In otherwords, one of ordinary skill in the art may refer to this technique ascoring. And if the bodily material that is cut is substantially solid,it will appear as generally cylindrically looking core or plug. AlthoughFIGS. 1-2 illustrate the laser emitters 10 in a generally concentricconfiguration, those skilled in the art will appreciate that there arenumerous other ways and configurations in which to arrange a pluralityof laser emitters. Additionally, although these two figures illustratean outer jacket 4 and an inner band 12, those of skill in the art willappreciate that distinct components need not be used, and the opticalfibers may be encapsulated within a single sleeve having a lumen.Accordingly, FIGS. 1-2, as well as FIG. 3 discussed below, are notintended to represent the only way that a laser catheter may beconfigured and constructed, and all such configurations andconstructions are within the knowledge of one skilled in the art areconsidered within the scope of this disclosure.

FIG. 3 is a cross-sectional perspective view of a laser catheteraccording to one embodiment of the present disclosure. A flexible distaltip 2 is provided, the distal tip 2 comprising a central or inner lumen14 provided substantially concentric with one or more annular arrays ofoptical fibers 10 and an outer jacket 4. An inner band 12 is provided ata far distal end of the tip 2. In the depicted embodiment, the innerband 12 has an orifice comprising an internal diameter that is smallerthan a minimum internal diameter of the inner lumen 14. The smaller sizeof orifice of the inner band 12 (either alone or in conjunction with thelocation and configuration of the laser emitters 10), in comparison tothe size of the lumen 14, ensures that the material will have a smallercross section than that of the lumen 14, thereby reducing the likelihoodthat the bodily material will become trapped or clogged in the lumen 14as it is aspirated therethrough. Although FIG. 3 depicts the orifice ofthe inner band 12 as being less than the minimal internal diameter ofthe inner lumen 14, the orifice of the inner band 12 may be equal to orgreater than the minimal internal diameter of the inner lumen 14.

The inner band 12 comprises a proximal end, a distal end, an interiorsurface and an exterior surface. When placed within the catheter 2, thedistal end of the inner band 12 is substantially aligned or flush withthe far distal end of the tip 15. The inner band 12 may be attached tothe catheter via numerous means known to one of ordinary skill in theart. For example, the dimension of the exterior diameter (orcircumference) of the inner band 12 may be slightly greater than thediameter (or circumference) of the lumen at the distal tip of thecatheter such that the inner band is press fit into the distal tip ofthe catheter 2. Additionally, the inner band 12 may be attached to thelumen by various known adhesives.

The interior surface of the inner band 12 may be straight or tapered.That is the interior diameters of the inner band may be the same ordifferent (e.g., smaller or larger) in comparison to one another. Forexample, the interior surface of the inner band 12 may be tapered suchthat the interior diameter at its proximal end is greater than theinterior diameter at its distal end.

Upon installation of the inner band 12 into the distal tip of thecatheter, the interior surface of the proximal end of the inner band 12may or may not be aligned or be flush with the surface of the lumen.Regardless of the alignment of the two surfaces, the lumen 14 mayinclude a transition portion that is tapered from the point at which theproximal end of the inner band 12 contacts the lumen until apredetermined point located proximally thereof. The taper may either anincreasing or decreasing taper as the lumen transitions proximally ofthe inner band 12. The tapered portion may also extend distally beyondthe proximal end of the inner band 12 and be used to affix the innerband 12 within the catheter. For example, as depicted in FIG. 3, aportion of the inner lumen 14 may comprise a tapered portion 19 toreceive and envelope a proximal portion of the inner band 12. The innerband 12 may also provide structural support to the distal end of thecatheter, and particularly to the distal ends of the fibers 10, whichare surrounded at an outer diameter by a tapered outer band 8.

Outer band 8 is tapered from its proximal end to its distal end 2,thereby facilitating the ease of movement of the catheter within a bloodvessel. The outer band 8 abuts outer jacket 4, and in order to furtherfacilitate movement of the catheter within the blood vessel, it may bepreferable that the exteriors of the outer band 8 and outer jacket 4 bealigned.

The catheter comprises a flexible distal end 2, the flexible distal end2 being operable by a user. The position of the distal end is controlledby one or more deflection means 16 which may include, but are notlimited to, pullwires, shaping wires, and similar force-transmittingfeatures controlled by a user at a user-proximal location of the device.Actuation of at least one deflection means 16 applies force to thedistal tip 2, thus deflecting the distal tip 2 from a longitudinal axisof the remainder of the catheter device. The deflection means allows theclinician to both create a pilot channel and subsequent larger channels,faster than conventional bulk ablation. For example, the clinicianinitially cuts the bodily material within the vascular system withoutdeflecting the distal end of the catheter. Then, the clinician deflectsthe distal end of the catheter using the deflection means andsubsequently cuts additional bodily material at the same generallocation within the subject's vascular system, thereby creating a largerchannel therethrough in comparison the channel created initiallycreated.

FIG. 4 is a schematic depicting a pulsed aspiration system 17 accordingto one embodiment of the present disclosure that may be connected to thelumen of the catheter to evacuate the ablated or cored bodily materialfrom a subject's vascular system using various embodiments of a cathetercomprising a distal tip having laser cutting means and/or mechanicalcutting means. As shown, a vacuum pump 18 is provided, the vacuum pump18 being interconnected to a pulse width modulator 20 in operativecommunication with at least one solenoid valve 22, the actuation ofwhich creates one or more pressure differentials to the aspirationsystem. Accordingly, rather than creating a constant suction pressurewithin the lumen of a catheter to evacuate cut and/or ablated bodilymaterial from a subject's vascular system, the aspiration system of thepresent disclosure applies alternative pressure(s), thereby creatingpulses of suction pressure within the lumen. Utilizing a series ofconstant and/or varying pressure pulses is potentially beneficial inaspirating bodily material, particularly when aspirating largercylindrically looking core or plug like shapes of bodily material.

A filter 24 is provided upstream of the solenoid valve 22, the filter 24provided for filtering debris and aspirated bodily material and also forproviding visual feedback to a user related to the type, quantity, andflow rate of material being removed from a patient. Fluid and materialis provided to the filter 24 via a catheter 26 interconnected to, forexample, an excimer laser system 28 for the treatment of peripheral andcoronary arterial disease such as the CVX-300 Excimer Laser System soldby the Spectranetics Corporation.

In various embodiments, a fluid collection jar 21 may also be providedin fluid communications with the vacuum pump 18. The fluid collectioncontainer 21, such as a jar, comprises one or more known devices forcollecting and filtering fluid removed from a patient. The container 21preferably comprises transparent sidewalls for providing visual feedbackto a user regarding flow-rate, content, coloration, etc. Filter meansare also provided for removing particulate from liquids. Those of skillin the art will appreciate that various types of fluid collectioncontainers may be used. The fluid collection container 21 and/or filter24 may also comprise one or more custom filter features with variousmesh sizes, capacities, etc. based on the specific application.

Pulse width modulator(s) 20 of the present disclosure provides forautomatic control and varied application of vacuum pressure to theremainder of the aspiration system, including features and devices of anexcimer laser system 28 provided in communication with the aspirationsystem 17. It will be recognized that where an excimer laser system 28is provided for cutting and ablating debris and particulate from a bloodvessel of a patient, efficient removal of such debris is still required.The present disclosure provides an aspiration system 17 for use with anexcimer laser cutting system 28 wherein blood and debris may beaspirated or removed in a pulsed fashion, thereby minimizing the amountof clean or healthy blood that is unnecessarily removed from a patient.

A pulse width modulator 20 is provided as a control means forcontrolling the opening and closing of at least one solenoid valve 22,the solenoid valve 22 provided for selective application and segregationof a vacuum pressure provided by the vacuum pump 18 from the remainderof a system. Controlling the frequency and duty cycle at which thesolenoid valve 22 opens and closes influences the pulse pattern, such asthe pulse frequency, the pulse width, the pulse pressure, the rate atwhich the pulse pressure increases and/or decreases, etc. The settingsfor the pulse width modulator 20 may be manually adjusted by a user toprovide a desired pulse pattern or the settings may be automaticallyadjusted by parameters stored within computer-readable medium controlledby a CPU. For example, during portions of a procedure where relativelylittle particulate is being ablated or cut from a patient's vascularsystem, the pulse width modulator 20 may be manipulated such thatapplications of vacuum forces are relatively far apart, thus removing aminimal amount of blood and fluid from a patient when such removal isnot necessary. Alternatively, where significant amounts of particulateare being ablated and removed from a patient, the pulse width modulatormay be manipulated or programmed to provide frequent constant and/orvarying vacuum pulses and remove greater amounts of fluid from thepatient.

The filter 24 preferably comprises a transparent device such that a useris provided with some level of visual feedback as to how much plaque orparticulate is being removed from a patient. Based on this feedback, forexample, a user can selectively manipulate the settings of the pulsewidth modulator 20 to alter the overall flow rate of material from apatient. In various embodiments, the pulse width modulator 20 and/orsolenoid valve 22 settings are controlled by a foot pedal, hand switch,or similar user-actuatable device.

The filter 24, vacuum pump 18, flow sensor(s) (not shown) and/orpressure sensor(s) (not shown) may output signals that are transmittedto the CPU controlling the pulse width modulator 20. Thecomputer-readable medium may include an algorithm, which receives theoutput signals and instructs the CPU how to adjusts the parameters atwhich the solenoid valve opens and closes.

An interface circuit 31 may also be provided for communication with thepulse-width modulator 20. The interface circuit is provided tocommunicate with, for example, the excimer laser system 28. The computerreadable medium and CPU discussed above may be located in the excimerlaser system 28. In addition to controlling the solenoid valve, theexcimer laser system may also provide for a clogged aspiration detectionsystem and control for a conduit-clearing mode based on variousadditional system parameters, including laser cutting operations.

FIG. 5 is a perspective view of a distal tip 30 of a catheter accordingto one embodiment of the present disclosure. FIG. 6 is a side elevationview thereof. FIG. 7 is a front elevation view thereof. As shown, thedistal tip 30 comprises a combination of a mechanical cutting means anda laser ablation means. Mechanical cutting means of FIGS. 5-7 includes asharp cutting edge or blade 32 that may be parallel to the longitudinalaxis of the catheter or it lumen. Laser ablation means of the depictedembodiments comprise an extending spiral or helix-type array of laseremitters provided in an approximate 360 degree pattern about thelongitudinal axis of the catheter and its lumen. The helical arraycomprises a first terminus 38 at a proximal end of the cutting edge 32and a second terminus 36 at a distal end of the cutting edge 32.Provided interior to the helical array is an inner lumen 40 throughwhich material dislodged or ablated by the mechanical cutting featureand/or the laser emitters 34 is removed from a patient.

In various embodiments, the inner lumen 40 comprises a lumen ofsubstantially circular cross-section with an internal diameter ofbetween approximately 0.050 inches and 0.10 inches. In certainembodiments, the inner lumen comprises a lumen of substantially circularcross-section with an internal diameter of between approximately 0.060inches and 0.090 inches. In a preferred embodiment, the inner lumencomprises a lumen of substantially circular cross-section with aninternal diameter of approximately 0.072 inches. In various embodiments,the distal tip 30 comprises an outer diameter of between approximately0.080 and 0.10 inches. In preferred embodiments, the distal tipcomprises an external diameter of approximately 0.090 inches.

It will be recognized that distal tips 30 of the present disclosure maybe provided with any number of laser emitters. However, in a particularembodiment, a distal tip is provided that comprises 50 optical fiberscapable of transmitting light of approximately 130 μm wavelength.

The cutting edge or blade of the present disclosure may be constructedof, for example, stainless steels, abrasive materials, diamond tip, etc.

The present disclosure further contemplates that various features ofFIGS. 5-7 may be inverted. Referring to FIG. 8, for example, there isdepicted in one embodiment, the laser emitters 808 along surface 804that may be substantially parallel to the longitudinal axis of thecatheter. Also included in this embodiment of the distal portion of thecatheter is a sharp cutting edge 812 or blade provided in a spiral orhelical configuration as it extends from the proximal end 816 of thesurface 804 to the distal end 820 of surface 804.

Various distal tip designs are contemplated by the present disclosure.Although particular embodiments are shown and described herein, thepresent disclosure is not so limited. Features of the present disclosuremay be provided in combination with various catheter distal end designs.For example, the configuration of the laser emitters 34 of FIGS. 5-7 mayarranged such that they extend spirally or helically but in a patterless than 360 degrees. Similarly, the sharp cutting edge or blade 32 inFIGS. 5-7 by be at an angle or offset from the longitudinal axis of thecatheter or it lumen.

Catheter distal tips of the present disclosure include, but are notlimited to, purely mechanical cutting devices provided in: circular,off-set, and semi-circular arrangements; various combinations ofmechanical and laser-ablative cutting systems; and purely laser-ablativecutting systems. For example, FIGS. 5-8 include tips capable of applyinglaser energy and/or mechanical force (or pressure) to core throughlesion material and create plug-type objects that can be aspiratedthrough the catheter in their entirety. However, certain aspects of thisdisclosure may be beneficial to various mechanical and/or other types ofmacerating type devices and catheter tips. For example, FIGS. 9 and 10illustrate mechanical tips that may be used to cut and/or maceratelesion-type tissue that may be capable of being aspirated in the mannerdiscussed within this disclosure.

Referring to FIGS. 9A & 9B, there is depicted a catheter 900 having atip 904 having a cutting blade with a plurality sharp vanes 908 ofcapable of cutting and/or macerating lesion tissue. FIG. 9A illustratesthe cutting blade in a retracted position so that the catheter cannavigate the subject's vasculature with minimal or no exposure of thevanes 908. FIG. 9B illustrates the cutting blade in the extendedposition. As the cutting blade extends, the vanes 908 extend and rotate,thereby cutting and/or macerating the tissue with which the vanes 908contact. Additionally, as the vanes 908 are extending and retracting,the pulsed aspiration system (previously discussed) can aspirate the cutand macerated tissue through the openings 912 between the vanes 908, thelumen 916 within the center of the blades and/or both. Furthermore,depending upon the internal configuration of the catheter and thechannels to the openings 912 and lumen 916, one or more aspirationsystems may be used in conjunction with the catheter.

Depending upon its use, the catheter may have differently shaped cuttingblades and vanes. For example, if it is desirable to use a catheter forlead extraction, it may be preferable that the size of the lumen beincreased, such as illustrated in FIGS. 10A-10B, thereby altering thesize and configuration of the blades. Similar to FIGS. 9A and 9B, FIGS.10A and 10B depict a catheter 1000 having a tip 1004 having a cuttingblade with a plurality sharp vanes 1008 capable of cutting and/ormacerating lesion tissue. However, in comparison to FIGS. 9A and 9B,FIGS. 10A and 10B have a larger lumen 1016 and larger openings 1012between the vanes 1008 because there are fewer vanes. Although these twofigures illustrate two types of cutting blades that can be used inconjunction with the aspiration system(s) discussed in this disclosure,those of skill in the art will appreciate that other configurations andtypes of cutting blades may be used in cooperation therewith.Accordingly, FIGS. 9-10 are not intended to represent the only ways thata mechanical, cutting-type catheter may be configured and constructed,and all such configurations and constructions are within the knowledgeof one skilled in the art are considered within the scope of thisdisclosure.

FIG. 11A is a cross-sectional elevation view of one embodiment of acatheter 50 comprising an outer surface 52 and an inner surface 54. Theinner surface 54 of the catheter 50 may comprise a helical structure 56extending from its distal to it proximal ends either continuously or forportions thereof. The helical structure 56 may comprise a polymerextrusion or metal insert extending radially inwardly from an innerdiameter of the inner surface 54 and along a length of the catheter 50in a helical or spiral manner. Alternatively, however, the helicalstructure 56 is provided as a recessed feature along the internalsurface 54 of the catheter 50. As the lesion material, either in theform of a plug or in macerated form enters the lumen formed by the innersurface 54, the helical structure 56 facilitates the spinning of thematerial within the lumen as it is aspirated, thereby potentiallyreducing the potential for clogging. Additionally, the helical structure56 may also macerate or further macerate the material, therebypotentially aiding and/or increasing the material's unimpeded travelfrom the distal to the proximal end.

A portion of a catheter 50 is depicted in FIGS. 11A-11B and nolimitation with respect to which portion or specific length is providedor implied. FIGS. 11A-11B are provided to depict the feature of thehelical structure 56 along an internal surface of the catheter 50. Sucha structure 56 may be provided along any length of the catheter,including a distal end of the catheter. Additionally, although notdepicted in FIGS. 11A-11B, various additional features as shown anddescribed herein may be provided in combination with the features ofFIGS. 11A-11B. For example, the catheter 50 may further comprise distalend cutting features such as laser ablative means and/or mechanical asshown and described herein. Additionally, vacuum pulsing and detectionssystems as shown and described may be provided in combination with thecatheter 50. It will be recognized that the helical structure 56depicted in FIGS. 11A-11B comprises a feature that may be integratedwith or provided in combination with various features shown anddescribed herein.

It will be recognized that the helical structure 56 of the catheter 50generally comprises an internal threaded feature. The helical structure56 may comprise various different thread characteristics, includingoverall length, pitch, diameter, etc. Preferably, however, the pitch andramp angle of the helical structure 56 is shallow enough to effectivelyablate occlusions within a blood vessel.

A number of variations and modifications of the disclosure can be used.It would be possible to provide for some features of the disclosurewithout providing others.

The present disclosure, in various aspects, embodiments, andconfigurations, includes components, methods, processes, systems and/orapparatus substantially as depicted and described herein, includingvarious aspects, embodiments, configurations, subcombinations, andsubsets thereof. Those of skill in the art will understand how to makeand use the various aspects, aspects, embodiments, and configurations,after understanding the present disclosure. The present disclosure, invarious aspects, embodiments, and configurations, includes providingdevices and processes in the absence of items not depicted and/ordescribed herein or in various aspects, embodiments, and configurationshereof, including in the absence of such items as may have been used inprevious devices or processes, e.g., for improving performance,achieving ease and\or reducing cost of implementation.

The foregoing discussion of the disclosure has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the disclosure to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of thedisclosure are grouped together in one or more, aspects, embodiments,and configurations for the purpose of streamlining the disclosure. Thefeatures of the aspects, embodiments, and configurations of thedisclosure may be combined in alternate aspects, embodiments, andconfigurations other than those discussed above. This method ofdisclosure is not to be interpreted as reflecting an intention that theclaimed disclosure requires more features than are expressly recited ineach claim. Rather, as the following claims reflect, inventive aspectslie in less than all features of a single foregoing disclosed aspects,embodiments, and configurations. Thus, the following claims are herebyincorporated into this Detailed Description, with each claim standing onits own as a separate preferred embodiment of the disclosure.

Moreover, though the description of the disclosure has includeddescription of one or more aspects, embodiments, or configurations andcertain variations and modifications, other variations, combinations,and modifications are within the scope of the disclosure, e.g., as maybe within the skill and knowledge of those in the art, afterunderstanding the present disclosure. It is intended to obtain rightswhich include alternative aspects, embodiments, and configurations tothe extent permitted, including alternate, interchangeable and/orequivalent structures, functions, ranges or steps to those claimed,whether or not such alternate, interchangeable and/or equivalentstructures, functions, ranges or steps are disclosed herein, and withoutintending to publicly dedicate any patentable subject matter.

What is claimed is:
 1. A catheter assembly comprising: a catheterdefining an inner lumen therein; a plurality of optical fibers providedin a helical arrangement concentric with the inner lumen; a mechanicalcutting feature including a portion proximate the plurality of opticalfibers; the plurality of optical fibers having a distal fiber and aproximal fiber, wherein the distal fiber is axially offset from theproximal fiber by a predetermined distance and wherein the mechanicalcutting feature extends along the predetermined distance; the pluralityof optical fibers provided external to the inner lumen, the inner lumenproviding a pathway for travel of material ablated by the opticalfibers; and wherein the helical arrangement extends 360 degrees about alongitudinal axis of the catheter.
 2. The catheter assembly of claim 1,wherein the mechanical cutting feature is disposed parallel with thelongitudinal axis of the catheter.
 3. The catheter assembly of claim 1,wherein each of the plurality of optical fibers are provided parallelwith the longitudinal axis of the catheter.
 4. The catheter assembly ofclaim 1, wherein the catheter comprises at least one deflection meansprovided along a length of the catheter, the at least one deflectionmeans operable to provide a deflection in a distal end of the catheterbased on user manipulation at a proximal end of the catheter.
 5. Thecatheter assembly of claim 1, wherein the plurality of optical fiberscomprises between thirty and sixty optical cutting fibers.